If f(x)=8x-3, what is the inverse function?

To obtain the inverse fucntion basically all we have to do is re-arrange the equation and the do a small trick of swaping x and f(x), which can be done either at the start or at the end. 

Assuming we leavce it for the end, the first step is to re-arrange the equation so that we have x=something

So first we move the 3 to the other side and get:

f(x)-3 = 8x

Then we divide both sides by 8 and get:

(f(x)-3)/8 = x

Now all we have to do is swap x anf f(x) round to get a standard function equation, and so we get:

f(x)= (x-3)/8

TA

Related Maths GCSE answers

All answers ▸

The probability that it rains on a given day is 0.15. The probability that a football match is cancelled when it rains is 0.65. If it doesn't rain, the probability that the match is not cancelled is 0.95. What is the chance that the match is cancelled?


Functions question: f(x) = 3x + 2a; g(x) = ax + 6; fg(x) = 12x + b. a and b are constants; Work out the value of b


A cuboid has dimensions: width = x+1, length = 2x-2, height = x+2. Work out the volume of this cuboid. Give your answer in terms of x.


Solve these simultaneous Equations: 4y-2x=8 and 2x-y=7